In the past, a chemically amplified negative resist composition composed of the combination of an acid generator and an alkali-soluble resin, such as a novolak resin or a polyhydroxy styrene, and an amino resin, such as a melamine resin or a urea-resin, has been used as a negative resist composition used for a process using an i-ray and a KrF excimer laser light (wavelength of 248 nm) as a light source (see Patent Document 1).
Also, as a negative resist composition used for a process using an ArF excimer laser of a short wavelength, there has been proposed a negative resist composition for improving transparency with respect to the ArF excimer laser, that is a composition, for example, which includes resin components having a carboxyl group, a crosslinking agent having an alcoholic hydroxyl group, and an acid generator.
This type of composition changes alkali solubility of the resin components to alkali insolubility by reacting the carboxyl group of the resin components with the alcoholic hydroxyl group of the crosslinking agent by action of acids generated from the acid generator.
Moreover, there has also been proposed a negative resist composition which includes a resin component having both a carboxyl group or a carboxylic acid ester group, and an alcoholic hydroxyl group and an acid generator and changes alkali solubility of the resin components to alkali insolubility by reacting the carboxyl group or the carboxylic acid ester group in the resin component with the alcoholic hydroxyl group by an action of acids generated from the acid generator (see, Non-Patent Documents 1 to 4 and Patent Document 2).
[Patent Document 1] Japanese Examined Patent Application Publication No. 8-3635
[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2000-206694
[Non-Patent Document 1] Journal of Photopolymer Science and Technology, Vol. 10, No. 4, pages 579 to 584 (1997)
[Non-Patent Document 2] Journal of Photopolymer Science and Technology, Vol. 11, No. 3, pages 507 to 512 (1998)
[Non-Patent Document 3] SPIE Advances in Resist Technology and Processing XIV, Vol. 3333, pages 417 to 424 (1998)
[Non-Patent Document 4] SPIE Advances in Resist Technology and Processing XIX, Vol. 4690, pages 94 to 100 (2002)